This invention relates to adapters for adapting tools, such as torque wrenches, for use in establishing the preload on bearings through the adjustment of relatively inaccessible nuts such as are found in the final drive of crawler-type vehicles.
Many crawler-type vehicles in use today employ drive sprockets and associated components configured generally as illustrated in U.S. Pat. No. 2,453,360, issued Nov. 9, 1948 to Burks. Typically, there is employed a sprocket shaft which is stationarily mounted and which receives a rotatable quill which, in turn, mounts the drive sprocket. The quill is disposed concentrically about the shaft, but out of contact therewith by two sets of bearings, one set typically being mounted in a wall of a final drive housing and the other being mounted near the outer end of the shaft by a bearing cage holder or the like.
Such bearings must be properly loaded through adjustment of interengaging parts. If the loading on the bearing is less than what it should be, the fit of the parts is relatively sloppy with the consequence that wear will occur at an excessive rate, resulting in premature failure. Conversely, if the bearings are overly loaded, again, excessive wear will occur with the resultant shortened life of the apparatus.
Proper loading of the bearings is generally achieved by the application of a rotative force to an adjustment nut to a predetermined torque. The application of proper torque to the adjustment nut can be easily attained at a place of manufacture of a crawler-type vehicle before the application of the track to the vehicle. However, when servicing the vehicle in the field when the track is mounted on the sprockets, the track sufficiently overhangs the end of the sprocket shaft so as to make the adjustment nut relatively inaccessible. Heretofore, the nut has been adjusted with long-handled spanner wrenches, the long handle being necessary to provide sufficient leverage to achieve the desired torque levels. However, because of the long handle, such spanner wrenches can be applied only at an angle to the nut and may slip off during the adjustment process. Moreover, torque is extremely difficult to measure when applies in the manner and it has been impossible to utilize a ratchet device with the result that, in many instances, the spanner wrench, after undergoing only the limited amount of travel permitted by the vehicle components in view of the long handle on the wrench, must be removed from the nut and reapplied thereto.
Consequently, field servicing of such units to obtain proper loading of the bearings has been haphazard and timeconsuming.